#include <iostream>
#include <fstream>
#include <cstring>

using namespace std;

ifstream f("text.in");
ofstream g("text.out");

int main()
{
    string s;
    getline(f, s);
    bool ok = false;
    int cuv = 2;
    long long int nr_lit = 0,sz;
    sz = s.size();
    for(int i = 0; i < sz; i++){
        if((s[i] >= 'a' && s[i] <= 'z') || (s[i] >= 'A' && s[i] <= 'Z'))
            nr_lit++,ok = true;
        if(s[i] == ' ' && ok == true)
            cuv++;
    }
    g << nr_lit / cuv;
    return 0;
}